merrill



(No Mpdel) G. W. MERRILL.

ROTATOR FOR SHIPS LOGS. No."272,146. `Padzen'ed Feb. v13, 1883.

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UNITED STATES PATENT OFFICE.

GEORGE W. MERRILL, OE BROOKLYN, NEW YORK, AssIGNoR To EIMsELE AND WILLIAM G. MERRILL, OE sAME PLAGE.

ROTA-roe FOR SHIPS Loes.

SPECIFICATION forming part of Letters Patent No. 272,146, dated February 13, 1883.

Application tiled December 5, 1882. (No model.)

To all whom it may concern Be itknown that I, GEORGE W. MERRILL, of Brooklyn, in the county ot' Kings and State ofNew York, have invented an improvement in Ships Logs,oi' which thefollowingisa speciiication.

Before my invention propellers for ships logs had been made with inclined fans around a central core, each fan or blade occupying a 1o radial ornearly radial position and spiral to the axis, so that the fans became the same as sectionsof a many-threaded screw. This propeller for the log Vhas considerable inertia and resistance in the water, and it is liable to jump out of the water and to pursue a zigzag course. Besides this, it is expensive to make, and it cannot be changed to rectify any inaccuracy in the registration ol the 10g. In addition to the foregoing disadvantages in the 2o propeller itself, the resistance offered in the water frequently causes the tow-line to snap, and the propeller islost, and frequently sharks snap at the propeller, and the shape is such Y that it dqes not slip out ot' the mouth, but is 25 liable to become caught in the teeth and the line broken. I

After many years `of experience and experi-` ment I have succeeded in devising and constructing a very simple propeller for ships 3o logs, which overcomes all the objections and difficulties heretofore known to me, and rendering the propeller so cheap and eiicient that the 'dead-reckoning ot' a ships course can be relied on to a greater extent than heretofore,

and the propeller is not liable to be lost, and if' it is lost another can be substituted at very little expense, and if the log does not correspond with the actual distance run the propeller can be adjusted at sea, even by a compara- 40 tively-inexperienced person.

In the drawings, Figure l Vis a view illustrating the manner in which this propeller for `logs is used, and. Fig. 2 is a side view, and

Fig. 3 an end view, ofthe propeller itself.

The registering mechanism a, that is employed, may be of any desired construction. A device of this character is shown in Letters Patent No. 263,936, heretofore granted to `W. G. and G. W. Merrill. From the registering 5o mechanism a line, b, passes to the eye c, or

other suitable attaching device, of the propel- 1er-blade d. This blade d is a twisted plate of metal, and it is quite long in proportion toits width-say about one and a half' inch Wide and twenty inches long, more or less. The twist or inclination ot' the edge to the axis is about the same as that-heretofore used in the blades of propellers i'orships logs, and the necessary extent of surface is obtained by the inclease of the length. By this construction of 6o propeller for ships7 logs the central core or axis is entirely dispensed with, the resistance in the' Water is lessened, the risk ofirregular action in thewateris prevented,because thedraft is at the end of a long body, and it Will keep on line with the cord or rope to the register, the Water will not be separated or lashed into foam by the propeller, and said propeller will glide through the water with scarcely any disturbance, and it will move in a regular screw 7o form through the water. It' any sh catches att-he propeller it is likely to slip out of the mouth, becauseit is the same size from end to end, or nearly so. Besides this, sea-weed is not liable to remain upon it as it draws out of the weed, because the blade isI the same size, or nearly so, from end to end. i

One ofthe importantfcatures ol' this invention is the ease with which it is adjusted.

In practical use it is found that the same log 8c will register differently upon different vessels, owing to the did'erence in the riding of the vessel and the disturbance ofthe waterin the wake of the vessel.

My propeller is made as a uniform twist S5 fromend to end; but it' the log` registers too great distance the error can be rectified by slightly untwisting the propeller, and the reverse it' the registration is too little. Suitable keys or bending-forks can be provided for in- 9o creasing or lessening the twist of the propeller-blade. A y

l claim as my invention- The propeller for ships logs, formed ofa long narrow blade twisted from end to end., and hav- 9'5 ing an attaching device at one end far the rope to the registering mechanism, substantially as set forth.

Signed by me this 2d day of December, A.

G. W. MERRILL. Witnesses: t

HAROLD SERRELL, CEAS. H. SMITH. 

